In Atlanta, Crawford scored 18 of his 23 points in the second half including the game-clinching three in the dying seconds of a nip-and-tuck contest.
"I just tried to get to my comfort zone, my sweet spot," Crawford told reporters. "I felt pretty good getting there. "I thought I got a good look, and it just happened to go down for me."
Al Horford gave the Hawks the lead at 85-84 with 46.6 seconds left.
Atlanta led for much of the game, but the lead changed four times over the final two minutes following an altercation which led to the ejection of Atlanta's Zaza Pachulia and Orlando's Jason Richardson.
"I thought we played with much more energy in the second half, and that got us back into it," said Orlando coach Stan Van Gundy. "But this is the playoffs and you can't play 24 minutes of defense."
In New Orleans, the Lakers pounced on the Hornets in the opening quarter and pulled away in the final period to regain home-court advantage.
In New York, the Celtics sprinted to a 22-5 lead eight minutes into the game and led comfortably from start to finish to take a commanding 3-0 lead in the series.
Boston will attempt to complete the sweep Sunday.
Paul Pierce led the Celtics with 38 points, Ray Allen hit eight three-pointers among his 32 points and Rajon Rondo had a triple-double with 15 points, 11 rebounds and a Celtics franchise playoff record 20 assists.
(Reporting by Mike Mouat in Windsor, Ontario. Editing by Alastair Himmer)